STRUCTURE OF THE SALIVARY GLANDS. 



1585 



Vessels. The arteries of the submaxillary gland are derived from the facial and 

 the sublingual branch of the lingual. The veins are from the corresponding ones. 

 The lymphatics go to the submaxillary glands. 



Nerves. The gland receives filaments from the sympathetic plexus accompa- 

 nying the facial artery, from the lingual nerve, and from the submaxillary ganglion. 



The Sublingual Gland. This differs from the two preceding glands in having 

 no capsule. It lies in loose areolar tissues on the mylo-hyoid muscle, at the front 

 part of the sublingual space. Its weight is 3 or 4 gm. Each gland rests internally 

 against the genio-glossus, and anteriorly they touch one another. They are more 

 readily separated into lobes than the others. Testut regards them as aggregations of 

 separate glands. The sublingual glands are covered by the mucous membrane of the 

 floor of the mouth, which they press upward into rounded swellings on either side 



FIG. 1345. 



Opening of anterior, 

 lingual glands 



Frenum 



Tongue, pulled upward 



Caruncle and opening of 

 submaxillary duct 



Genio-glossus 



Sublingual 

 gland 



Genio-hyoid 

 Mylo-hyoid 



Cut fibres of digastric 



Section across anterior part of floor of mouth, showing relations of sublingual glands to mucous membrane and 



muscles. 



of the beginning of the frenum. The lingual nerve and the submaxillary duct are 

 on the inner side. The sublingual or Rivinus' ducts vary in number from four 

 to twenty or more. They open for the most part in the floor of the mouth, but 

 some may join Wharton's duct. Bartholin' s duct is an inconstant one, larger 

 than the others, that usually opens close to the outer side of Wharton's duct, which 

 it follows. 



Vessels. The arteries are from the sublingual branch of the lingual and the 

 submental branch of the facial, which latter sends minute twigs through the mylo-hyoid 

 muscle. The blood escapes into the ranine vein. The lymphatics run to the sub- 

 maxillary nodes. 



Nerves are from the sympathetic, the lingual, the submaxillary ganglion, and, 

 according to many, from the chorda tympani. 



STRUCTURE OF THE SALIVARY GLANDS. 



The three chief salivary glands possess in common the tubo-alveolar type of 

 structure; depending upon the character of their secreting cells and products, the func- 

 tionating organs represent both the serous and mucous varieties. The parotid is a 

 pure serous gland ; the submaxillary is a mixed one, the alveoli containing serous cells 

 predominating ; the sublingual, also a mixed gland, consists chiefly of mucous alveoli, 

 the serous cells being limited to the marginal groups constituting the demilunes of 

 Heidenhain, 



